This paper shows (a) how the concept of the linguistic market can be operationalized as an index to enable its inclusion as a factor in variationist analysis and (b) how this index helps to explain sociolinguistic variation in a diglossic situation. To do this, sociolinguistic interviews were conducted in Swiss Standard German among 16 L1-dialect-speakers aged between 19 and 40 from Biel/Bienne in western Switzerland. Drawing from participants’ self-assessments of the importance of Standard German in their professional life, a linguistic market index (LMI) was created and cross-validated with external assessments. Our variationist analysis considered four phonetic-phonological variables—/k/, /ç/, /aː/, /ɛ-ɛː/—for which typical Swiss variants (i.e., sociolinguistic stereotypes) exist. Findings show that the LMI is crucial for explaining variation in all the variables tested. Other social (i.e., gender and formality of the language production task) and linguistic factors (e.g., phonetic environment) show partial effects as well.
